13 Mar
2019
13 Mar
'19
8:53 a.m.
On 3/13/19 7:10 AM, William Donzelli via cctalk wrote:
Be careful handing out the praise. The idea of adding
a external
signals and biases to crystal detectors was an old trick from the
1920s. No one really knew what was going on, and no one really used
this technology, simply because performance was beyond horrid - even
original Audions worked better.
Sure--I recall reading an article from an issue of QST from the 1920s
that reported an "oscillating crystal". One has to believe that
negative resistance in solid materials had to have been discovered
several times.
There is a web site, http://www.sparkbangbuzz.com/ that demonstrates
that a strip of galvanized steel can make a quite successful
negative-resistance device, including several transmitters. The fellow
even shows how to make a memristor using some brass and sulfur.
--Chuck